Actor and comedian Cheech Marin, probably best known as half of the Cheech and Chong duo, has millions of fans around the world. But not many of them know that Cheech actually has another passion for collecting Chicano art. Saturday, the first museum ever dedicated solely to Mexican-American artists, opens in Riverside. It is called "The Cheech," or more formally, The Cheech Marin Center for Chicano Art & Culture.